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2 years ago

Select all of the following expressions that are equivalent to 16a+40 .

1 answer:

lina2011 [118]2 years ago

5 0

The first one is true
4(4a+10) is
16 a + 40 after distribution

The second one is also true
2(8a+20)
16a + 40 after distribution

Third is not true
4a(4+10a)
16a + 40a^2 after distribution

Last one is also true
8(2a+5)
16a + 40 after distribution

Hope this helps :)

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I need help I don’t understand it

tiny-mole [99]

Shidddd lil buddy, try the 3rd one

4 0

2 years ago

The radii of two right circular cylinders are in the ratio 3 : 4 and their heights are in the ratio 1 : 2. Calculate the ratio o

bezimeni [28]

Answer:

18.852:50.272

Step-by-step explanation:

Step one:

given

The radii of two right circular cylinders are in the ratio 3 : 4

r1= 3

r2= 4

Their heights are in the ratio 1 : 2

h1= 1

h2= 2

Step two:

The expression for the curve surface area is

CSA= 2πrh

CAS1= 2πr1h1

CAS1= 2*3.142*3*1

CAS1= 18.852

CAS2= 2πr2h2

CAS2= 2*3.142*4*2

CAS1= 50.272

The ratio of their curved surface areas

=18.852:50.272

3 0

2 years ago

What weight of dry substance is in 150g of a 3% substance solution? What weight of an 8% solution can we have with the same weig

Pavlova-9 [17]

The answers are: 4.5 g and 56.25 g respectively.

Since the first type of measurement in this question is weight or mass, I'll suppose that the percentage concentration is % mass/mass. For that type of concentration measurement, just multiply the percentage by the total mass to get the mass of the wanted material.
So 150 g * 3% = 150 g * 0.03 = 4.5g

For the 8% solution with the same amount of dry substance, use the ratio of percentages, multiplied by the mass of the first solution to get the wanted amount of new solution:
3/8 * 150 g = 56.35 g

5 0

2 years ago

30 points!! What is the sum of the first six terms of the series? 48 - 12 + 3 - 0.75 +...

Lunna [17]

Answer:

The sum of the first six terms is 38.39

Step-by-step explanation:

This is a geometric sequence since the common difference between each term is $-\frac{1}{4}$

Thus, $r=-\frac{1}{4}$

To find the sum of first six terms, we need to find the fifth and sixth term of the sequence.

To find the fifth term:

The general form of geometric sequence is $a_{n}=a_{1} \cdot r^{n-1}$

To find the fifth term, substitute $n=5$ in $a_{n}=a_{1} \cdot r^{n-1}$

$\begin{aligned}a_{5} &=(48) \cdot\left(-\frac{1}{4}\right)^{5-1} \\&=(48) \cdot\left(-\frac{1}{4}\right)^{4} \\&=(48)\left(\frac{1}{256}\right) \\a_{5} &=0.1875\end{aligned}$

To find the sixth term, substitute $n=6$ in $a_{n}=a_{1} \cdot r^{n-1}$

$\begin{aligned}a_{6} &=(48) \cdot\left(-\frac{1}{4}\right)^{6-1} \\&=(48) \cdot\left(-\frac{1}{4}\right)^{5} \\&=(48)\left(-\frac{1}{1024}\right) \\a_{5} &=-0.046875\end{aligned}$

To find the sum of the first six terms:

The general formula to find Sn for $|r|$ is $S_{n}=\frac{a\left(1-r^{n}\right)}{1-r}$

$\begin{aligned}S_{6} &=\frac{48\left(1-\left(-\frac{1}{4}\right)^{6}\right)}{1-\left(-\frac{1}{4}\right)} \\&=\frac{48\left(1-\frac{1}{4096}\right)}{1+\frac{1}{4096}} \\&=\frac{48(0.95)}{5} \\&=\frac{48(0.9998)}{5} \\&=\frac{48(0.9998)}{5} \\&=\frac{47.9904}{5} \\&=38.39\end{aligned}$

Thus, the sum of first six terms is 38.39

5 0

2 years ago

The number 100 ten times as much as 1tenth1/10

Afina-wow [57]

The answer is 0.1 i think

4 0

3 years ago